Unit filter assembly



March 31, 1964 R. J. BOYLAN 3,127,259

UNIT FILTER ASSEMBLY Filed Sept. 28, 1960 IIIIIIIIIIIIIIA 2 26 $1614 24l h h Ii 'IIIIIIIIIIIIIII ROBERT J BOYLAN ATTORNEY United States PatentFiled Sept. 28, 1960, Ser. No. 58,978 1 Claim. (Cl. 55-511) The presentinvention relates to filter apparatus and more particularly to unitfilter apparatus including removable gas cleaning filter medium.

In accordance with the present invention, an improved unit filterstructure is provided which is economical and efficient to construct andmaintain and which permits ready, secure installation and ready removalof the filter medium from its supporting frame. In addition, theimproved unit filter structure of the present invention can beconveniently and efiiciently adapted to unit filter arrangements whichinclude either disposable or renewable filter medium.

Various other features of the present invention will become obvious toone skilled in the art upon reading the disclosure set forthhereinafter.

More particularly, the present invention provides a filter assemblycomprising an open-ended border frame member having an upstream gasinlet and a downstream gas outlet, a pad of filter medium sized to fitwithin the border frame member, a first tape member mounted to theborder frame member, the first tape member being provided with a firstseries of fastener elements mounted thereon, a second tape membermounted to the pad of filter medium, and a second series of fasteningelements mounted to the second tape member removably engageable with thefirst series of fastening elements whereby the filter medium and pad canbe removably mounted in the border frame member.

It is to be understood that various changes can be made by one skilledin the art in the arrangement, form and construction of the apparatusdisclosed herein without departing from the scope or spirit of thepresent invention.

Referring to the drawing which discloses two advantageous embodiments ofthe present invention:

FIGURE 1 is an isometric view of an open-ended border frame memberdisclosing a first tape member mounted to the side flange thereof;

FIGURE 2 is an isometric view of a pad of filter medium sized to bemounted in the border frame member of FIGURE 1 and including a secondtape member arranged to cooperate with the first tape member in theframe member of FIGURE 1;

FIGURE 3 is an enlarged cross-sectional view of the pad and framemembers of FIGURES 1 and 2 in assembled position;

FIGURE 4 is a greatly enlarged cross-sectional view taken in a planepassing through line 44 of FIGURE 3, disclosing hook and eye-shaped pilethreads on facing tape members in interlocking engagement; and,

FIGURE 5 is an isometric view of a corner portion of an open-endedborder frame member, disclosing a modified structure for fastening thefilter pad to the border frame member.

Referring to FIGURE 1 of the drawings, open-ended border frame member 2having upstream gas inlet 3 and downstream gas outlet 4 is disclosed.Frame member 2 3,127,259 Patented Mar. 31, 1964 includes side wallmembers 6 and side flange members 7, which define a gas passage opening.It is to be understood that the frame member can be made from any one ofa number of suitable rigid materials, such as metal or cardboard, and,as can be seen in FIGURE 3 of the drawing, frame member 2 serves toaccommodate a filter pad such as at 8 (FIGURE 2), sized to fit into theframe member so that the edges thereof extend substantially adjacent theside wall members 6 of the frame. Flter pad 8 can be made from any oneof a number of suitable filter materials known in the art. For example,a pad made from a suitable foam polyurethane or fiber glass material canbe used.

To hold pad 8 in securely fastened position in frame 2 and to permitready removal thereof for purposes of renewal or replacement, a novelarrangement is disclosed. This arrangement includes a first tape member12 fixedly motmted to the inner face of side flanges 7 of border member2 by some suitable means such as gluing or stapling (FIGURE 1). A secondtape member 13 is fixedly mounted by some equally suitable means to pad8 along the periphery of the upstream face thereof (FIG- URE 2). Thetape members 12 and 13 are sized to cooperatively contact each other infacing relationship when pad 8 is inserted in frame 2. The tape members12 and 13 includes a series of hook and eye-shaped pile threads 24, 26,respectively (FIGURE 4). In this connection, attention is directed toUS. Patent No. 2,717,437, issued to G. De Mestral on September 13, 1955,which suggests hook-shaped pile thread tape similar to thatabovedescribed. It is to be noted that when tapes 12, 13 are placed infacing contact, the hooks 24 and eyes 26 of the tapes interlock tomaintain filter pad 8 in securely fastened position in border framemember 2. Thus, in a simple, straightforward manner, a filter pad can bereadily installed in its border frame member with a minimum of parts andwith a minimum of operating steps. Further, the pad can be readilyremoved for purposes of replacement or renewal, the particular tapearrangement including the hook and eye-shaped pile threads, as disclosedin FIGURES 1-4, lending itself readily to cleaning operations in theevent the pad is of the renewable type.

It is to be understood that the present invention is not limited to thespecific fastening arrangement. as disclosed in FIGURES 1-4. In thisconnection, attention is directed to the structure disclosed in FIGURE 5wherein male portion 31 of a conventional zipper is fixedly attached toborder frame member 32 and female portion 33 of such conventional zipperis attached to a pad of filter medium 34, the male and female portionsof the zippers being interlocked and disengaged by means of aconventional slider 36. Thus, pad 34 can be securely fastened in itsborder frame member in a simple, straightward operation and removed inan equally simple, straightforward manner.

The invention claimed is:

A filter assembly comprising a set of connected side Wall members havingside flanges extending normal thereto and along an edge thereof todefine an open-ended border frame member having an upstream gas inletand a downstream gas outlet, said side flanges extending inwardly fromsaid side wall members and adjacent said downstream gas outlet, a pad offilter medium including an upstream and downstream face and sized to fitwithin said border frame member with the edges thereof extendingsubstantially adjacent the inner face of said side Wall members, a firsttape member mounted-to the in ner face of said side flanges of saidborder frame member, said first tape member being provided with a firstseries of fastener elements mounted thereto and extending toward saidupstream gas inlet, a second tape member mounted to said pad of filtermedium along the periphery of said downstream face thereof, and a secondseries of fastener elements mounted to said second tape member andextending outwardly therefrom away from said downstream face of saidpadoffilter medium, said first and second series of fastener elements beingin the form of interlockably engageable and disengageable pile threads,said pad of filter medium being located within said border frame memberwith said pile threads of said tape members interlockably engaged, saidinterlockably engageable and disengageable pile threads constituting 4':means removably mounting said filter pad in said border frame memberwith said filter pad upstream of said side flanges whereby said tapemembers are urged into fast engagement with each other by the gas streamduring gas treating operations to further retain said pad in said frame.

References Cited in the file of this patent UNITED STATES PATENTS MillerMar. 28, 1961

